Alternating-current motor.



A. KIMBLE. ALTERNATING CURRENT MOTOR. APPLIOATION FILED MAY 15, 1905.

1,004,437, Patented Sept.- v.26, 1911.

' 'UNITED sTATEs PATENT OFFICE.

AUSTIN KIMBLE, OF CHICAGO, ILLINOIS, ASSIGNOR, BY DIRECT AND MESNASSIGN- MENTS, 'I'O KIMBLE ELECTRIC COMPANY.. OE CHICAGO, ILLINOIS, ACORPORATION OF ILLINOIS.

ALTERNArI-No-CURRENT Moron.

Application vled May 15,

To all whom it may concern:

Be it known that I, AUSTIN KIMBLE, a citizen of the United States ofAme-rica, and aresident of'Chicag J, in the county of Cook and Stateof'Illinois', have invented certain new and useful Improvements inAlternating-Current Motors, of which the following is a specification.

The main object of this `invention is to provide a simple and inprvedform of alternating currentmotor adapted to be conveniently held in thehand of an operator for loperating han-d Cools,- rIlhis object isaccomplished by the device shown in the accompanying "drawings, inwhich:

Figure 1 is a longitudinal section of an alternating current motoradapted to be held in. the 'hand of an operator, the wiring being showndiagrammatically and, indicated by dotted lines. Fig. 2 is a transversesection on the line 2 2 of Fig-1, and shows the shape of the disks whichmake up the laminated field and armature magnetic frames, the section ofthe windings of wire being indicated by intersecting cross hatchine.

In the construction shown in the drawings",- the field magnet is rigidlymounted on a hollow shaft 4e, which is held in a fixed position wit-hinthe' handle 5. The shaft 4 is .preferably hollow and serves as aconvenient retainer for the electrical conductors which furnish power tothe motor. One portion G of the shaft i is threaded and the thin disksof sheet iron which form the laminated field frame are clamped togetherendwise upon said threaded portion by the nuts .7. The plates which makeup the eld frame are cut to form, when assembled, a core havingsubstantially cylindrical outer contour and having longitudinal grooves8 at opposite sides thereof. The field wind-. ings 9 are seated in thegrooves 8 and the ends of said windings enter apertures 10 and extendthrough the hollow shaft 4f, one of said ends being connected with oneof the brushes 11 and the other extending out through the handle to formo1 e of the line conductors L. The other line conductor L connects withthe other brush '.1'.

The armature frame consists of a core 12 formed of a plurality of ringshaped disks of sheet iron clamped together between the hearing pieces13 and 14 by means of longitudinally disposed bolts 15. The berringSpecification of Letters Patent. Patented Sept. 26, 1911.

1905. 'serial No. 260,453.

:pieces 13 and 14 are journaled tofrotate on f the shaft l andthe.armature core 12 forms ia ring surrounding the field core 3. The diskswhich form the core 12 are stamped with opposed inner and outer radiallydisposed recesses 16 which forfn longitudinally dsposed grooves in thecore when said @plates are assembled; The armature windlEings 17 extendaround the armature core in f a longitudinal direction, each coiloccupying one of said opposing pairs of inner and fouter grooves 16.The. joints between suc.-

eessive armature coils are connectedby wires 18 with the commutatorsegmentsk 19, or may be connected in any usual man-ner. The commutatoris rigidly secured toy the. bearing piece 14 and rotates therewith. The'bearing piece 13 is externally threaded at 22v for attaching a chuck orother device-to be rotated by the motor.

The armature windings consist f insulated .iron wire which is seated inthe grooves or slots of the varmature core and so arranged as tosubstantially ll said slots and to a large extent take the place of theportions -of the laminated core which were eut away to form the slots.The armature winding thus forms a part of the laminated core structure,and insures a substantially uniform. path for the magnetic lines offorce of the field, and thereby insures a minimum fluctuation of thefield flux during the rotation of the armature. By eliminating thefluctuation of the field flux, that part of the induced current in thearmature windings which is due tol such fluctuation is eliminated.

As will be seen from the drawings, the field and armature windings areconnected through the commutator in series with each other.

By using iron wire for winding the armature, I. am able 'to regulate themotor by shifting the position of the brushes with respect to the fieldpoles. The resistance of the iron wire. serves to prevent sparking atthe brushes due to the short-circuiting of the armature windings by thedisplacement of the brushes and by the passing of the brushes from onecommutator segment to another.

In the operationI of the device shown, the handle 5is held in the handof the operator and the flow of the current through the armature isregulated by shifting the speed.

brushes. The knurled knob 20 which controls the shifting of the brushes,is located in convenient position for being grasped by the thumb andforefinger of the same hand by which the operator holds the handle 5.Then the brushes'll are in the neutral position, the motor will run atits highest `When the brushes are shifted to- Ward one side from such.`osition, the armature re-actance opposes t e flow of' current andreduces the speed. When the brushes arrive at. a position at rightangles to the neutral position, the motor will cease to operate.Shifting the brushes beyond this line causes the motor to operate in theopposite direction.

A What I claim as my invention, anddesire to secure by Letters Patent,is:

1. In a device of the class described, the combination of a handle, aield core rigidly secured to said handle in alinement therewith, anannular armature core surrounding said field core and journaled on saidhandle, windings of Wire on said-cores, a commuta- 'tor secured to saidarmature and rotatable therewith, and a brush holder rotatably mountedbetween said handle' and ield eore and adapted to hold the brushes inContactl with the commutator, said brush holder having an annular partinsulated from the brushes and located in Aaxial alinement With thelhandle and adapted to be shifted by the thumb and forefinger of the handof an operator, when the 'same hand is grip ing the handle as in guidingthe operation o the de-l vloe.

2. The combination o a handle, an electric motor mounted thereon andadapted to operate a tool carried thereby, a slee-ve rotatably mountedon said handle in alinement therewith and adapted to be rotated by thethumb and orefinger. of `-an opera# tors hand While the same hand isgripping said handle as for guiding the tool, and

ineans adapted to control the speed of 'said4 Copies of this patent maybe obtained for five cents each, by addressing the ommissoner oflaterts,

v Washington, D. C.

